Method and apparatus for finishing ball raceways or the like



Aug. 12, 1941. T. C. PEW

METHOD AND APPARATUS FOR FINISHING BALL RAcEw-AYs oR THE LIKE Filed June 26, 1939 4 Sheets-Sheet 1 l INVENTOR.

- ,'T/'amas Ci 79a() BYi Y y aATTLNEYS T. C. PEW

Aug. l2, 1941.

METHOD AND APPARATUS FOR FINISHING BALL RACEWAYS OR THE LIKE Filed June 26, 1939 4 sheets-sneer INVENTOR, Tomas C. Pew B@ @da wff;

- ATTORNEY@ www lmI Aug. 12, 1941. 3, pEw 2,252,096

'METHOD AND APPARATUS FOR FINISHING BALL RAcEwAYs 0R THB LIKE Filed June 2e, 19:59 4 sheets-sheet sA ATT ORNEYS Aug.` `l2, 1941. T. c. PEw 2,252,096

METHOD AND APPARATUS FOR FINISHINGl BALL RAGEWAYS OR TI-IE LIKE Filed June 26, 1959 4 Sheets-Sheet 4 INVENTOR.

. A LT/offjas Cf Pew Patented ug. 12,1941

UNITED STAT-Es PATENTx ori-ics METHUD AND APPARATUS FOR FINISHING BALL BACEWAYS R THE LIKE Thomas C. Pew, Ann Arbor, Mich., asslgnor to Hoover Ball & Bearing Company, Ann Arbor, Mich., a corporation oi' Michigan VApplication June 26, 1939, Serial No. 281,072

l 14 Claims. This invention relates to an apparatusfor and .method of inishing the surface of a machine gated circumferential contact with the surface of the raceway, and more or less wraps around the Fig. '2 is a top plan view of the apparatus.

Fig. 3 is a view illustrating the position 'of the work and hone before the hone is applied to the work.

Fig. 4 is a cross sectional view |taken substantially on line 4--4 of Fig. 2.

raceway for a short distance while at the same time the arrangement provides for movement of the'hone in the finishing process transversely of the raceway groove. The difculties of the past have largely been that where the hone is partially Wrapped around the race, it could not bev moved crosswise. Movement of the hone relative to the race is desirable, for otherwise there is a tendency to cut grooves in the iinished surface. The movement permits of changing the location of particles and permits escape of particles which might otherwise scratch the Surface if retained in the same location. A hone of cylindrical form which engages in a circumferential groove can be moved transversely of the race in the honing actionlbut a cylindrical form only provides for a line contact, whereas a surface contact is desired.

In accordance with this invention the hone can have a wrapping surface contact with the race and at the same time be shifted or oscillated transversely of the race member in the honing` action. The invention is applicable to the honing of both interior and exterior races, and the above remarks are to be considered in this light. The

term hone is used in a broad sense, it being understood that rough finishes may be obtained by the use of an abrasive member having a consid-- erable' abrasive action, and i'lner nishes can be obtained by an'abrasive member having a. finer action and not such a great cutting action. Both of these items are intended to be, coveredby the use of. the term hone.

An arrangement for carrying outthe inven tion is shown in the accompanying drawings.

Fig. 1 is a general view of a machine showing a race with an exterior groove in position on a spindle` and illustrating the general features of a machine. f

p Fig. 5 is a cross sectional View taken substantially on line 5-5 of Fig. 2.

Fig. 6 is an enlarged cross sectional view taken substantially on linev6'-6 of Fig. 2 showing the hone mounting and manipulating device.

Fig. 'I is a cross sectional view taken. substantially online 1-1 of Fig. 6 showing the arrangement for oscillating the hone.

Fig. 8 is a sectional view similar to Fig. 'I showing the device applied to a race with an interior groove.

Fig. 9 is a sectional view taken substantially on line 9--9 of Fig. 8. i .n

Fig. 10 is a plan view of a modiiied form.

Fig. 11 is a cross sectional view taken sub stantially online li-li of Fig. 10. l

Fig. 12isa view looking in the direction of line l2-i2 of Fig. 10 showing eccentric gears.

Fig. 13 is a view illustrating how two operations may be performed on 'a race with one setting of the race.

Fig. 14 is a view showing the relative positions of the hone and race in one extreme position of the hone.

Fig. 15 is a view similar to Fig. 14 vshowing the relative positions of thehone and race in another extreme position of the hone.

Fig. 16 is a view taken substantially on line lG-IS of Fig. 14, showing how the hone wraps the race to obtain a surface contact. u

The mechanism for the mounting of the race and for the mounting and movement of the hone vmay take various forms, but as shown in Fig. 1

the Work shown -in the form of a race I' with an exterior groove is mounted vupon a spindle 2 raceway. 'I'he head and sub-bed 8 may be shifted axially to remove the hone from the raceway, thatisto a position similar to the dotted line position shown in Fig. 1.

The hone is illustrated at I and is carried by the head 1. When the hone is in the dotted line position shown in Fig. 1 the head 1 has been shifted rearwardly and the sub-bed 5 with. the head shifted to the right. To bring the hone into position, the sub-bed is shifted to the left against :the stop 8 where it is latched by latch device 9, and then the head 1 may be shifted forwardly to cause the hone to engage the work. The head 1 may be shifted by means of gear Il operating a screw l2 or other similar device. The structure thus far described is exemplary of means for mounting the work andthe hone.

Referring now to Fig. 2, the drive for the hone Y maybe through a pulley I5, shaft I6, and a gear l1 meshing with gear IB, and then through meshing gears I9 and 25. The provision of these several gears makes it feasible for changing the gears, particularly for reasons as will later appear, although in the arrangement shown in Fig. 2 they are merely for transmitting the driving action. The rotary power is transmitted to a bevel gear 2l which meshes with bevel gear 22. In fact, the beveled gear 22 is a combined bevel gear and spur gear having teeth 23 which mesh with a gear 24. A crank arm 25 is mounted on the gear 24 preferably in an adjustable manner. To this end a plate 26 is slidably mounted on the gear 24 and the plate carries a stud 21 'which amounts to a crank (Figs. 2 andll). Plate 26 has elongated apertures by means of which it may be adjusted and held to the gear 24 by screws 28 passing therethrough. Once the plate has been properly adjusted, such adjustment may be maintained by drilling a hole through the plate and into the gear and by the insertion of a pin through the aligned holes. Such holes for receiving locking pins are illustrated at 29. The adjustment of the plate 26 determines the throw of the crank stud 21.

A gear 30 is connected to the other end of the arm 25 as at 3l, and it will be seen that rotation of the gear 24 oscillates the gear 30. The throw of the pin 21, that is the distance of the center of the pin from the center of the gear 24 determines the angularity of the oscillation of the gear 30.

In making reference to Fig. 6 it will be seen that the gear 30 meshes with the two smaller gears 32 and 33, and the reduction is advantageously two to one so that if the gear 3B is oscillated through 55, for example, the gears 32 and 33 oscillate through 110, This assembly has been found to be an expedient arrangement. The gears 30 and 33 are keyed to shafts 34 and 35, which are mounted in bearings as illustrated, and the ends of these shafts have enlarged hollow heads 3B and 31. Within these hollow heads are positioned eccentric bushings 38. As shown in Fig. 7 these bushings maybe made of two matched pieces with the dividing lines therebetween illustrated at 40.

A stud is located within each bushing, the studs being illustrated at 4l and they have heads 42 so that the studs are held in position by the bushings, and this is the reason for making the bushings in two matched halves so that they can be placed around the journaled portions of the studs. After the bushings and studs are located, they may be held in position by lrings 43 secured to the ends of the shafts 34 and 35, and the bushings are shouldered to receive the rings as illustrated. The bushings are keyed'or pinned to the shafts 34 and 35 to oscillate therewith. To this end a pin 45 may pass through the recessed head of each shaft and into the bushing, the pin advantageously being disposed on the line separation between the two halves of the bushing: These pins are shown in Fig. '1 and one is illustrated in Fig. 4.

The. exposed ends of the studs 4l are of enlarged formation, this formation being illustrated at 45 (Fig. 4) and are`of U-shape and arranged to be crossed by closure plates 41. A holder for a hone which may take the form of a tube of square formation is slidably mounted in the two enlarged portions of the studs. Such a holder is illustrated at 50 and it may have an adjustable screw backing member 5| which bears against the body vof the hone i0 slidably mounted in the tubular holden. 'I'he holder may be spring pressed toward the work, to which end one end of the holder is closed by a plate 53, and coil springs 54 connect the plate and projections 55 on the oscillating stud 4l adjacent this rear end of the holder. f

Before proceeding with the modified forms the operation of the structure may be considered. With the race in position on the spindle 2 and the hone in the dotted line positionvshown in Fig. 1, in which position the hone is retracted from the spindle, the sub-bed 5 may be shifted to the left to align the hone with the work. The parts are now in a position as illustrated in Fig. 3. Thenby turning the wheel Il the head 1 is advanced toward the work and the hone is brought up against the work as illustrated in Figs. 6, 7 and 14 to 16, inclusive. The bushings are so arranged as tooscillate the hone to and from the extreme positions substantially shown in Figs. 14 and 15. The cross dimensions of the hone are preferably somewhat less than the cross dimensions of the raceway. With a 55 throw ofthe gear 24, the gears 32 and 33, and likewise the eccentric bushings, are given a throw. It has been found that an eccentricity of the bushings of about .012 of an inch is satisfactory for use with raceways for balls ranging from 11g to of an inch in diameter. By this I mean that the centers are .012 of an inch off from each other, which would give, on a complete rotation, a movement of .024 of an inch. The springs 54 urge the hone with light pressure against the work, say from 8 ounces to about a pound and a half, although this is variable. It would probably be desirable to increase the pressure in cases where a rough finish is desired.

Assuming that the hone has the shape illustrated in Figs. 14; 15 and 16, it oscillates to and from the positions shown in Figs. 14 and 15, while the springs urge the holder forward so that there is a slight reciprocating-movement of the holder and its hone. As the hone wears away the springs take up the loss, but from time to time the hone may be advanced by the screw 5l. Thus the hone constantly moves back and forth across the race- Way together with a movement in and out radially while maintaining a surface contact by the slight wrapping action illustrated in Fig. 16. When the hone is in the position shown in Fig'. 14, the raceway is engaged along a narrow surface having the circumferential extent shown in Fig. 16, and as it moves across to the Fig. 15 position, the surface engaged progressively moves across the surface of the groove. Theoretically, it may be considered that there is only a line contact, but as a matter of fact there is a slight surface contact. To illustrate what is meant, lines are shown in Figs. 14 and 15 more'or less dividing the surface into areas a, representing the surface I more quietly.l

thereto. V y acted upon by' coil springs 63 and connected to ferent positions of lthe hone. It will be round that the-hone keeps itself ldressed to vthe true shape o1' the raceway. The

`radius on the hone will be generated thereon to 5 the radius of the raceway less the amount of the eccentricity. The end of the hone ,will shape itself to the circumferential contour of the raceway so that the hone has a wrapping action as.

shown inFig. 16. The contour ofthe end of the hone, when viewed after the manner of Fig. 16, will be such thatythe hone tsthat portion of the 'race with which it contacts, and this `shape will be generated on the hone. lInother Words, vwhenix the hone is in the Fig. position, it contacts 15 Way. Thus it will be seen that there is a surface contact between the hone and the raceway, with a constant shift of the hone across the raceway, which prevents the cutting of grooves or the marring of the surface, and permits of the escape of abrasive particles. By Way of example it might be stated that good results have been obtained where the work was given 1100 R.. P. M. with about 1300 oscillations per minute of-the hone; that is, 1300 complete cycles of the hone from theFig. 14 position to the Fig. 15 position and back. However, at the commencement of the operation, it maybe desirable to rotate the work at a low R. P. M., say about 600, and to have a high hone oscillation, say about 1500 per minute; while at the finish of an operation, vthe work may be speeded up to 1500 R. P. M. and thev oscillations of the hone diminished to rabout 600 R. P. M. These figures are given `for exemplary purposes only and are not to be construed as limiting the invention. 40

This manner of honing the race does notdestroy the contour, and provides a highly nished surface which materially increases the life of the bearing and makes the bearing function much For honing a race whichhas an interiorgroove, an arrangement shown in Figs. 8 and 9 may be employed. In this case a support is carried by the studs 41| and this support slidably carries the hone holder 6I positioned at right angles The hone holder has a back plate 62 thesupport as at '64 for holding the hone lila against the race. With this arrangement, since the hone has been turned through 90, it is only ,necessary to shift the bushings 38a through 90 to thus get the same movement as that previously described. lAs a matter of fact, the hone may be disposed at most any angle and the same hone movement may be imparted thereto by relatively adjusting the bushings to correspond to the angle of the hone.

As shown in Fig. 13'two operations may be given to a race with one mounting of the race. The spindle and race shown in this view bear the same characters as those previously used, and two hones may be mounted after themanner illustrated in Figs. 1 and 2 to approach the work from different sides. The hone 10b, as shown, may 70 give the work a roughiinish, and then it may be retractedyto the dotted line position Where it is inoperative and the hone Inc moved into engagement with the work to give the final nish. As a matter of fact several hones may be thus CII grouped around the work to perform as many rough and ilnal finishing operations.

The arrangement thus far described is such that the hone `moves', with uniform action; that is to say, its oscillations and speed .ot movement is uniform with a constant R. P. M. of the driving mechanism. In Figs. 10, 11 and 12 an arrangement is shown for giving to the hone recurring variations in its speed of movement and also to break up Vthe regularity of the recurring variations. I'he arrangement shown in Fig. 10 and in Fig. 11 is substantially the same as that shown in Fig. 2, and the corresponding parts are given the same reference characters. Howeven the gears i'iaV and lila are eccentric gears, as shown in Fig. 12. Thus with the shaft I6 operating at a uniform R.. P. M., the speed of the gear Ita` varies. Accordingly, thefspeed of movement of gear., 22 similarly varies, "and this varies the speed of movement of the hone in its oscillations. That is to say, in some positions of the hone in its cycleiof movement, the hone will move faster than in other positions. Now in order tobreak up the regular recurring manner of such variation in the speed of the hone, gears 19a and 20a, instead of having' a direct or uniform ratio relative to each other, are arranged to have some odd ratio. For example, these two gears may have an odd arrangement of teeth, such, for example, as 63 to 33, or vice versa, and 47 to 49, or vice versa, or some other arrangement of this character. These gures are only given as examples. With this arrangement, the regular recurring variation in the R. P. M. of the gear 24 is broken upso that the variation in movements of the hone takes place at variousplaces'in its cycle o f movement. This is one reason for providing the gear arrangement shown, since different arrangements may befobtained by merely changing the -gears Ila and i'8a, as Well also as the gears i9a and 20a. The eccentric gears may be used with or without the odd ratio gears lila and 20a, but in this case the movements of the hone varies in a regular recurring manner. The structure shown in Fig. 11 is no different than the corresponding structure of these parts in the apparatus shown in Fig. 2, but Fig. 1l may be employed for the purpose of showing the parts in Fig. 2 in a diierent position. i

In some of the claims appended hereto, use is made of the term hone." to use such a term for the sake of brevity, and

l the Wordis to be construed to mean any suitable abrasive or polishing element. Some of the claims make use 'of the term "wrap" or wrapping in describing the contact between the hone and the race. This means that the hone contacts'with the race measured circumferentially for a distance as distinguished from a line contact. Some of the claims, particularlythe apparatus claim,'call for an apparatus for acting upon a ball bearing race or the like. This language is Yto be construed to cover any device, regardless of Whether or not it is a ball bearing race', and so the race under pressure a hone having a cross dimension less than the cross dimension of the race and having ajdimension measured circumferentially of the race such that the hone has a 'wrapping fit with the race, causing relative ro- It is advantageous latingfthe hone crosswise of the race.

2. The method of nnishingfthe surface of a ball bearing race which comprises applying tov the race under yielding pressure a 'hone having a cross dimension slightly less than that of the cross dimension of the race and having a dimension measured circumferentially of the race such that the hone has a wrapping t with the race, causing' relative rotation between the race and the hone and oscillating the hone crosswise of the race whereby the hone follows the contour of the transverse curve of the race incident to the yielding pressure.

3. The method of finishing a surface of a machine element, which surface is of curved formation transversely and longitudinally, applying to the race yieldably and under pressure a hone having a dimension measured longitudinally of lthe surface such that the hone has a wrapping fit on the longitudinally curved surface, causing relative movement between the surface and the hone for the presentation of successive longitudinally related portions of the surface to the hone, oscillating thev hone transversely of the surface whereby the hone follows the transverse curvature of the surface, the hone having dimensions measured transversely of the surface whereby it is adapted to present different surfaces for contact with successive transversely related portions of the surface as the hone oscillates.

4. The method of finishing a surface of a machine element, which surface is of curved formation transversely and longitudinally, applying to the race yieldably and under pressure a hone having a dimension measured longitudinally of the surface such that the hone has a wrapping fit on the longitudinally curved surface, causing relative movement between the surface and the hone for the presentation of successive longitudinally related portions of the surface to the hone, oscillating the hone transversely of the surface whereby the hone follows the transverse curvature of the surface, the hone having dimensions measured transversely of the surface whereby it is adapted to present different surfaces for contact with successive transversely related portions of the surface as the hone oscillates and varying the speed of movement of theV hone in its oscillation.

5. 'Ihe method of finishing a surface of a machine element, which surface is of curved formation transversely and longitudinally, applying to the race yieldably and-under pressure a hone having a dimension measured longitudinally of the surface such that the hone has a wrapping fit on the longitudinally curved surface, causing' relative movement between the surface and the hone for the presentation of successive longitudinally related portions of the surface to the hone, oscillating the hone transversely of the surface whereby the hone follows the transverse curvature of the surface, the hone having dimensions measured transversely of the surface whereby it is adapted to present different surfaces for contact with successive transversely related portions of the surface as the hone oscillates, and varying the speed of movement of the hone in its oscillations in an irregularly recurring manner.

6. The method of finishing the surface of aA ball bearing race which comprises applying to the race yieldingly and under pressure a hone having dimensions measured longitudinally of the race such that the hone has a wrappin! fit longitudinally on the surface. causing relative rotation between the race and the hone for the presentation of successive longitudinally related portions of the surface to the hone, said hone having dimensions measured transversely of the surface such that it is adapted to present different surfaces for contact with successive transversely related portions of the surface, and oscillating the hone transversely of the surface whereby the honefollows the transverse curvature and presents such different surfaces to the successive transversely related portions of the race surface. A 7. The method of finishing the surface of a ball bearing race which comprisesfapplying to the race yieldingly and under pressure a hone having dimensions `measured longitudinally of the race such that the hone has a wrapping fit longitudinally on the surface, causing relative rotation between the race and the hone for the presentation of successive longitudinally related portions of the surface to the hone, said hone having dimensions measured transversely of the surface such that it is adapted to present different surfaces for contact with successive transversely related portions of the surface, and oscillating the hone transversely of the surface whereby the hone follows the transverse curvature and presents such different surfaces to the successive transversely related portions of the race surface and varying the speed of movement of the hone in its oscillatory motion.

8. The method of finishing the surface of a ball bearing race which comprises applying to the race yieldingly and under pressure a. hone having dimensions measured longitudinally of the race such that the hone has a wrapping fit longitudinally on the surface, causing relative rotation between .the race and the hone for the presentation of successive longitudinally related portions of the surface to the hone, said hone having dimensions measured transversely of the surface such that it is adapted to present different surfaces for contact with successive transversely related portions of the surface, and oscillating the hone transversely of the surface whereby the hone follows the transverse curva-- ture and presents such different surfaces to the successive transversely related portions of the race surface and varying speed of movement of the hone in its oscillatory motion in an irregularly recurring manner.

9. The method of nishing the surface of a ball bearing race which comprises applying to the race yieldingly and under pressure a hone having dimensions measured longitudinally of the surface such that the hone has a wrapping fit on the longitudinally curved surface and having dimensions measured transversely of the race surface substantiallyA equal to the transverse dimension of the race surface less the amount of the below mentioned oscillation to be vgiven to the hone, causing relative rotation between the race and the hone for the presenrace surface having a dimension in one direction for a mapping' t with the race surface and a dimension in a direction perpendicular to the first dimension for the presentation of different parts of its own surface to successive transversely related portions of the race surface, a holder for the hone, means for yieldingly applying the hone to the race surface, means for oscillating the hone transversely of the race surface including an eccentric bushing, and means for oscillating the bushing.

11. An apparatus for finishing the surface'of a member such as a ball bearing race or the like which comprises, means for holding and'.

rotating the race, a honelfor application to the race surface having a` dimension in one direction for a wrapping .t with the race surface and a dimension in a direction perpendicular to the first dimension for the presentation of different parts of its own surface to successive transversely relatedportions of the race surface, a holder for the hone including means for yieldingly applying the hone to the race surface, eccentric bushings supporting the holder, and means for oscillating the bushings to oscillate the hone transversely across the race surface.

12. An apparatus for finishing the surface of a member such as a ball bearing race or the like which comprises,. means for holding and rotating the race, a hone for application to the race surface having a dimension in' one direction fora wrapping fit with the race surface and a dimension in a direction perpendicular to Y theI first dimension for the presentation of difvferent partsy of its own surface to successive transversely related portions of the race surface, a holder for the hone including means for yieldingly applying the hone to the race surface, rockable means for supporting the holder and for oscillating the hone transversely across the race surface, means for operating the rockable means including eccentric gears for varying the speed of movement of the hone in its oscillatory action.

13. An apparatus fornnishing the surface of like which comprises, means for holding and rotating the race, a hone for application to the race surface having a dimension in one direction for a wrapping nt with the race surface and 4 a dimension in a direction perpendicular to the first dimension for the presentation of different parts of its own surface to successive transversely related portions of the race surface, a holder for the hone including means for yieldingly applying the hone to the race surface, rockable means for supporting the holder and,for oscillating the hone transversely across the race surface, means for operating the rockable means including eccentric gears for varying the speed of movement of the hone in its oscillatory action, and also including related gears with an odd ratio for causing an irregular recurrence of the variation in the speed of movement of the hone.-

14. An apparatus for finishing the surface of a member such as a ball bearing race or the like which comprises, means for holding and rotating the race, a hone for application to the race of its own surface to successive transversely related portions of the race surface, a holder for the hone including means for yieldingly applying the hone to the race surface, rockable means for supporting the holder and for oscillating the hone transversely across the race surface, means for operating the rockable means including eccentric gears fcr varying vthe speed ofmovementV of the hone in its oscillatory action, and also including means for causing an irregular recurrence of the variation in the speed of movement of the hone. s

- THOMAS C. PEW. 

